Foundry mold forming



E. L. FRANKENSTEIN FOUNDRY MOLD FORMING Nov. 15, 1960 2,959,828

2 Sheets-Sheet 1 Filed June 50, 1958 Fig.2.

INVENTOR.

His ATTORNEYS Edgar L. Frankenstein Nov. 15, 1960 Filed June 30, 1958 E.L. FRANKENSTEIN FOUNDRY MOLD FORMING 2 sheets-sheet 2 I I I l INVENTOR.Edgar L. Frankenstein WMF M His ATTORNEYS United Sttes Patent FOUNDRYMOLD FORMING Edgar L. Frankenstein, Zelienople, Pa, assignor to HermanPneumatic Machine Company, Pittsburgh, Pa., a I

This invention relates to foundry mold forming method and apparatus andhas to do with the formation of foundry molds by jolting and squeezing.It is conventional in forming foundry molds to dump mold formingmaterial such as sand into a flask assembled to a pattern so that thesand lies upon the pattern within the flask. The flask, pattern and sandmay be periodically jolted to assist in distributing and compacting thesand in the flask. Also the sand may be squeezed against the pattern.

In order to get the most effective results of jolting and squeezing itis desirable to accomplish them simultaneously. However, satisfactoryresults have not been obtained in the efforts prior to my invention tosimultaneously jolt and squeeze foundry molds of finely divided moldforming material. The jolting has interfered with effective squeezing.The jolting involves periodic movement of the flask, pattern and sandthrough a short distance which may be perhaps of the order of an inch,the jolting frequency being perhaps of the order of 300 cycles perminute. When an attempt has been made to squeeze the sand during joltingthe squeezing pressure has been affected by the jolting so that thesqueezing pressure alternately increases and decreases, resulting in aninferior mold. Also the Wear on parts of the apparatus has beenexcessive.

I have devised foundry mold forming method and apparatus obviating thedisadvantages of the prior methods and apparatus above referred to. Myfoundry mold forming apparatus may comprise means for supporting apattern with an open-topped flask mounted thereon and finely dividedmold forming material in the flask against the pattern, means forsubjecting the supporting means to periodic jolting action to assist indistributing and compacting the mold forming material in the flask andmeans carried by the supporting means for squeez: ing the mold formingmaterial in the flask against the pattern. I desirably provide mountingmeans carried by the supporting means and extending upwardly therefrom,a head carried by the mounting means above the supporting means andmeans carried by the head for squeezing the mold forming material in theflask against the pattern. The mounting means may comprise posts at thecorners of the supporting means carried thereby and extending upwardlytherefrom, and a head may be carried by the posts above the supportingmeans, and means may be carried by the head for squeezing the moldforming material in the flask against the pattern.

I preferably provide vertically oriented cylinder means mounted in thehead which as above indicated is carried by the supporting means,together with piston means operable in the cylinder means and meanscarried by the piston means for squeezing the mold forming material inthe flask against the pattern. A plurality of vertically orientedcylinders are preferably mounted in the head and a piston is providedwhich is operable in each cylinder, and means are carried by the pistonsfor squeezing the mold forming material in the flask against thepattern.

"too

I preferably provide a separate squeezing member carried by each pistonas disclosed in co-pending application Serial No. 741,826, filed June13, 1958, now abandoned.

Means are preferablyprovided for separately operating the squeezingmembers so that they may move downwardly to different extents whereby topromote optimum distribution and compression of the mold formingmaterial in the flask despite difference in depth of the mold formingmaterial above the pattern at different. portions of the pattern. Themeans for separately operating the squeezing members may when desirableact on at least certain of the squeezing members with differentpressures.

I provide a method of forming a foundry mold comprising placing finelydivided mold form-ing material adjacent a pattern in a flask,periodically jolting the flask, pattern and mold forming material toassist in distributing and compacting the mold forming material in theflask and simultaneously with the jolting squeezing the mold formingmaterial in the flask against the pattern by squeezing pressure whichgradually increases to a maximumand then is maintained substantiallyconstant despite the simultaneous jolting. The squeezing pressure ispreferably separately applied at different portions of the pattern andmay be so applied through squeezing pressure of different magnitude.Thus, I form a mold of optimum characteristics with the sand or othermold forming material compacted to the desired extent through-v out themold, either uniformly or non-uniformly as conditions may dictate.

Other details, objects and advantages of the invention will becomeapparent as the following description of a present preferred embodimentthereof and a present preferred method of practicing the same proceeds.

In the accompanying drawings I have shown a present preferred embodimentof the invention and have illustrated a present preferred method of.practicing the same in which Figure '1 is an elevationalview, with afragment in vertical cross section offoundry mold jolting and squeezingapparatus; a 1

Figure 2 is a top plan view of the apparatus shown in Figure 1; and I VFigure 3 is a vertical cross-sectional view taken on the line III-III ofFigureZ. j 7

Referring now more particularly to the drawings, my foundry moldsqueezing apparatus comprises a base designated generally by referencenumeral 2 for supporting in fixed position a carrier plate 3 upon whichis mounted a pattern plate 4 carrying a pattern 5, a. flask 6 beingassembled to the pattern plate and pattern as shown in Figure 3 so as tosurround the pattern and extend thereabove. The flask 6 has at its upperportion a grid consisting of crisscross bars 7 each of which has itsupper edge generally in the plane of the upper surface of the flask andextends downwardly to aid in anchoring the finely divided mold formingmaterial but not far enough to interfere with the pattern. The grid bars7 are arranged in rows at right angles to each other and form square orrectangular openings in the top of the flask, which openings arerespectively adapted to receive the squeezing members presently to bedescribed. Finely divided mold forming material such for example asmolding sand is designated by reference numeral 8 and is introduced intothe flask upon and about thepattern as shown in Figure 3. My mechanismisto eifectively squeeze the sand within the flask against the patternduring jolting of the mold as will presently be described to form a moldof optimum characteristics suitable for the casting of metal.

A post 9 extends upwardly, from the base 2 ateac'h of the four cornersthereof, and mounted upon the four posts 9 in fixed position above thebase is a head designated generally by reference numeral 10. Mounted inthe head are twenty-four cylinders each designated by reference numeral11, the cylinders being arranged in four rows of six cylinders each asclearly shown in Figures 1 and 3.

A piston operates in each cylinder 11. Connected with each such pistonis a piston rod 13 which projects downwardly and out of the bottom ofthe cylinder and has a squeezing member 14 connected therewith at itsbottom. The cylinders 11 remain stationary in the head but therespective pistons are adapted to move up and down in the cylinders andto move the squeezing members 14 with them. Each squeezing membercarries a guide rod 15 passing through a guiding opening 16 in thecylinder.

Fluid under pressure, desirably hydraulic fluid, is introduced through afluid supply conduit 17 into a header 18 whence the fluid passes throughbranch conduits 19 to individual connections 20 to the respectivecylinders 11, a pressure control valve 21 being provided in eachconnection 20 so that the pressure of fluid admitted to each cylindermay be individually controlled. The fluid under pressure is admitted atthe top of each cylinder 11 above the piston therein. An exhaustconnection 22 extends from the lower part of each cylinder below thepiston therein, the exhaust pipes 22 entering branch conduits 23communicating with an exhaust header 24 which in turn communicates withan exhaust conduit 25.

As shown in Figure 3 the pattern 5 is of non-uniform height. After thecarrier plate 3, pattern plate 4 with the pattern 5 thereon, and flask 6have been assembled in the relationship shown in Figure 3 sand isintroduced into the flask atop and about the pattern. The sand asintroduced is relatively loose and uncompacted. Normally the flask isfilled full of sand and the sand is struck off at the upper surface ofthe flask by any suitable tool.

The squeezing members 14 are of square or rectangular shape and arepositioned so that when they move downwardly they enter and largely fillthe square or rectangular spaces in the grid 7 at the upper portion ofthe flask 6. When the sand is to be compacted fluid under pressure isadmitted to the upper ends of the cylinders 11 and the respectivesqueezing members 14 are by the fluid under pressure pressed downwardlyto compact the sand against and about the pattern. Since the pattern isof non-uniform height, initially there is a deeper layer of sand atop ashallower portion of the pattern than atop a higher portion of thepattern. As the squeezing members move downwardly there is some lateralflowing or shifting of sand in the flask and the sand flows in suchmanner as to largely equalize the depth of sand above the patterndespite the fact that the top of the pattern is not in a singlehorizontal plane. I do not mean that the depth of the sand above thepattern is made precisely uniform throughout the top area of the patterndue to the flow of sand under the action of the squeezing members butthe sand flow causes some sand at portions where the sand is initiallydeeper to flow laterally to other portions of the mold. Since thesqueezing members 14 are individually operated, each by its own pistonoperating in its own cylinder, each may move downwardly within the flaskand compress or compact the sand to whatever extent the pressure behindits piston causes it to move. Thus the respective squeezing members movedownwardly to diflerent extents as shown in Figure 3. If the pressurecontrol valves 21 are all set for the same pressure the sand beneath therespective squeezing members will be compacted to substantially the samepressure despite the diflerence in height in the various portions of thepattern and hence of the inner mold wall formed against the pattern. Inthis way I may form a mold of unprecedented uniformity of compactness.On the other hand if a mold is desired having certain portions of thesand compacted to a greater extent than other portions this may readilybe accomplished by appropriate adjustment of the pressure control valves21.

After squeezing a mold the squeezing members 14 may be retractedupwardly by reversing the flow of fluid under pressure, i.e., byadmitting fluid under pressure through the conduit 25 and exhausting thefluid above the pistons in the cylinders 11 through the conduit 17. The

foundry mold squeezing method and apparatus are claimed in the abovementioned copending application.

The base 2 of the mold squeezing apparatus has integral therewith anddisposed centrally thereof a downwardly projecting piston 26 whichoperates in a vertical cylinder 27 of a jolt base 28. The jolt base 28is preferably mounted upon and fixedly bolted to a stationary concretefoundation. The base 2 of the squeezing apparatus has at its bottom feet29 each disposed above superposed discs 30 and 31 disposed in one of aplurality of bores 32 in the jolt base 28. Preferably each disc 31 isresilient and made of rubber or rubber-like material. The discs 30 maybe made of steel or similar material. When the discs 31 are not undercompression except by the Weight of the discs 30 the upper portions ofthe discs 30 project above the tops of the bores 32. In Figure 1 thediscs 31 are under compression and the feet 29 are shown as havingpressed the discs 30 down so as to be completely within the bores 32.

A jolt valve is shown at 33 and may be of conventional construction.Fluid under pressure, normally air, is supplied to the jolt valve 33through a pipe 34 and is by the valve 33 admitted periodically throughthe passage 35 to the space in the cylinder 27 below the piston 26 so asto raise the piston and hence the base 2 of the squeezing apparatusrelatively to the jolt base 28. The extent to which the squeezingapparatus may be raised is limited by an adjustable nut 36 on the lowerthreaded end of a rod 37 threaded to the lower portion of the base 2 at38. The rod 37 also prevents turning of the squeezing apparatus base 2relatively to the jolt base 28. The amplitude of jolting of thesqueezing apparatus relatively to the jolt base is of the order of aninch or slightly more. The jolt valve operates in conventional manner asknown to those skilled in the art so as to jolt the squeezing apparatusrelatively to the jolt base perhaps four or five times per second. Thevalve may be operated by an adjustable rod 38 connected with thesqueezing apparatus base 2 at 39 and adapted to engage a valve operatingplunger 40 upon downward movement of the squeezing apparatus base 2carrying the piston 26. The carrier plate 3 may be dowelled to thesqueezing apparatus base 2 to maintain the same against relativetransverse or turning movement.

Jolting mechanism of the general type shown at the lower portion ofFigure 3 is conventional and well known to those skilled in the art so Ihave not shown the details of the jolting mechanism. However, it is newso far as I am aware to mount the squeezing apparatus upon the joltingmechanism so that a mold may be simultaneously jolted and squeezedwithout the disadvantages occurring as above pointed out when thesqueeze head is mounted separately from the jolting mechanism. Bysimultaneously squeezing the mold through the use of squeezing mechanismmounted to move up and down with the mold as the mold is jolted a moreuniformly packed mold of optimum molding characteristics is produced. Aconstantly applied pressure may be exerted against the top of the moldduring jolting which causes the mold forming material to flow withunprecedented uniformity into low density areas. Especial advantages areobtained through mounting on the jolting mechanism the self-adjustingsqueeze head having the individual squeezing members.

While I have shown and described a present preferred embodiment of theinvention and have illustrated a present preferred method of practicingthe same it is to be distinctly understood that the invention is notlimited thereto but may be otherwise variously embodied and practicedwithin the scope of the following claims.

I claim:

1. Foundry mold forming apparatus comprising means for supporting apattern with an open-topped flask mounted thereon and finely dividedmold forming material in the flask against the pattern, jolting meansfor subjecting the means for supporting the pattern to periodic joltingaction to assist in distributing and compacting the mold formingmaterial in the'flask, means for supporting the jolting means, saidmeans for supporting the jolting means being separate from the firstmentroned supporting means, and means carried by the means forsupporting the pattern for squeezing the mold formmg material in theflask against the pattern.

2. Foundry mold forming apparatus comprising means for supporting apattern with an open-topped flask mounted thereon and finely dividedmold forming material in the flask against the pattern, jolting meansfor subecting the means for supporting the pattern to periodic oltingaction to assist in distributing and compacting the mold formingmaterial in the flask, means for supportng the jolting means, said meansfor supporting the joltmg means being separate from the first mentionedsupporting means, mounting means carried by the means for supporting thepattern means and extending upwardly therefrom, a head carried by themounting means above the means for supporting the pattern and meanscarried by the head for squeezing the mold forming material in the flaskagainst the pattern.

3. Foundry mold forming apparatus comprising means for supporting apattern with an open-topped flask mounted thereon and finely dividedmold forming material in the flask against the pattern, jolting meansfor subjecting the means for supporting the pattern to pcriodic joltingaction to assist in distributing and compactmg the mold forming materialin the flask, means for supporting the jolting means, said means forsupporting the jolting means being separate from the first mentronedsupporting means, posts at the corners of the means for supporting thepattern carried thereby and extending upwardly therefrom, a head carriedby the posts above the means for supporting the pattern and meanscarried by the head for squeezing the mold forming material in the flaskagainst the pattern.

4. Foundry mold forming apparatus comprising means for supporting apattern with an open-topped flask mounted thereon and finely dividedmold forming material in the flask against the pattern, jolting meansfor subjecting the means for supporting the pattern to periodic joltingaction to assist in distributing and compacting the mold formingmaterial in the flask, means for supporting the jolting means, saidmeans for supporting the jolting means being separate from the firstmentioned supporting means, mounting means carried by the means forsupporting the pattern and extending upwardly therefrom, a head carriedby the mounting means above the means for supporting the pattern,vertically oriented cylinder means mounted in the head, piston meansoperable in the cylinder means and means carried by the piston means forsqueezing the mold forming material in the flask against the pattern.

5. Foundry mold forming apparatus comprising means for supporting apattern with an open-topped flask mounted thereon and finely dividedmold forming material in the flask against the pattern, jolting meansfor subjecting the means for supporting the pattern to pe riodic joltingaction to assist in distributing and compacting the mold formingmaterial in the flask, means for supporting the jolting means, saidmeans for supporting the jolting means being separate from the firstmentioned supporting means, mounting means carried by the means forsupporting the pattern and extending upwardly there from, a head carriedby the mounting means above the means for supporting the pattern, aplurality of vertically oriented cylinders mounted in the head, a pistonoperable in each cylinder and means carried by the pistons for squeezingthe mold forming material in the flask against the pattern.

6. Foundry mold forming apparatus comprising means for supporting apattern with an open-topped flask mounted thereon and finely dividedmold forming material in the flask against the pattern, jolting meansfor subjecting the means for supporting the pat-tern to pcriodic joltingaction to assist in distributing and compacting the mold formingmaterial in the flask, means for supporting the jolting means, saidmeans for supporting the jolting means being separate from the firstmentioned supporting means, mounting means carried by the means forsupporting the pattern and extending upwardly therefrom, a head carriedby the mounting means above the means for supporting the pattern, aplurality of vertically oriented cylinders mounted in the head, a pistonoperable in each cylinder and a separate squeezing member carried byeach piston for squeezing the mold forming material in the flask againstthe pattern.

7. Foundry mold forming apparatus comprising means for supporting apattern with an open-topped flask mount ed thereon and finely dividedmold forming material in the flask against the pattern, jolting meansfor subjecting the means for supporting the pattern periodic joltingaction to assist in distributing and compacting the mold formingmaterial in the flask, means for supporting the jolting means, saidmeans for supporting the jolting means being separate from the firstmentioned supporting means, mounting means carried by the means forsupporting the pattern and extending upwardly therefrom, a head carriedby the mounting means above the means for supporting the pattern, aplurality of squeezing members carried by the head for generally side byside vertically downward movement into the open top of the flask andagainst the mold forming material to press the mold forming materialagainst the pattern and means separately operating the squeezing membersso that they may move downwardly to different extents whereby to promoteoptimum distribution and compression of the mold forming material in theflask despite ditference in depth of the mold forming material above thepattern at different portions of the pattern.

8. Foundry mold forming apparatus comprising means for supporting apattern with an open-topped flask mounted thereon and finely dividedmold forming material in the flask against the pattern, jolting meansfor subjecting the means for supporting the flask to periodic joltingaction to assist in distributing and compacting the mold formingmaterial in the flask, means for supporting the jolting means, saidmeans for supporting the jolting means being separate from the firstmentioned supporting means, mounting means carried by the means forsupporting the pat-tern and extending upwardly therefrom, a head carriedby the mounting means above the means for supporting the pattern, aplurality of squeezing members carried by the head for generally side byside vertically downward movement into the open top of the flask andagainst the mold forming material to press the mold forming materialagainst the pattern and means separately operating the squeezing membersso that they may move downwardly to different extents whereby to promoteoptimum distribution and compression of the mold forming material in theflask despite difference in depth of the mold forming material above thepattern at diflerent portions of the pattern, the means separatelyoperating the squeezing merry bers acting on at least certain of thesqueezing members FOREIGN PATENTS with difierempressures- 384,014 GreatBritain Dec. 1, 1932 References Cited in the file of this patent 8394Great Bntam 1935 UNITED STATES PATENTS 5 OTHER REFERENCES 450,521Mistelski Apr. 14, 1891 The Foundry, May 1950, pages 250, 253-254 and723,529 Hudson Mar. 24, 1903 256.

1,605,096 Campbell Nov. 2, 1926

